i sailed on a boat that has a beige --looks like desert sand color--worked well. every shade off arctic white FOR CARS is 10 degrees of heat absorption. my formosa uses forest green..lol--my ericson i have concord--i willl probably use concord with the green and make a mess..LOL---under sail it isnt important--you get the breezes--at anchor it makes a difference in cabin top temp, thus interior temp... tarp acts as an attic--keeps the warmth until a breeze blows it out...but prevents the sun from beating on the coach house roof..we also used a brown tarp--didnt seem to make any difference on the boat...in cars, i know the 10 degree thing works--havent found it to be of any consequence in the water, as the water tempo also affects interior comfort....so is all personal preference, as far as i can see--i donot use marinas, so i always face wind, but in a marina it might make a slight diffeence as the wind isnt always on the bow creating a good breeze through the boat....bird poo--i have a kat--he takes care of that--he is always on watch and stray burdeez get caught or batted....LOL....